Conventional contactor auxiliary switches comprise contacts that are typically required to handle 10 milliamps to 5 amps. In order to switch this range of current in harsh environments the contact surfaces require silver plating for currents levels from 100 mA to 5 A and the contact surfaces require gold plating for current levels below 100 mA. Therefore, in order to work across the required 10 mA to 5 A current range, the contacts are electro-plated with gold over silver plating.
In some conventional contactor auxiliary switches, the contacts are in the form of rectangular electrical pads that are embedded on the substrate of a printed circuit board. Further, the electrical pads have exposed contact surfaces. For this type of contactor auxiliary switch, in order to work across the required 10 mA to 5 A current range, the contact surfaces of the electrical pads must also be electro-plated with gold over silver plating. However, this type of electro-plating on a printed circuit board is not a currently available option.